'Half brothers' in the Bible

He went to his father's home in Ophrah and murdered his half-brothers, the seventy legitimate sons of Jerub-Baal, on one stone. Only Jotham, Jerub-Baal's youngest son, escaped, because he hid.

God repaid Abimelech for the evil he did to his father by murdering his seventy half-brothers.

So Jephthah left his half-brothers and lived in the land of Tob. Lawless men joined Jephthah's gang and traveled with him.